Blocking exhaust cross-over - LA intake manifold

[GoodysGotaCuda]

Whats the best method for blocking off an exhaust cross-over on an LA/318?  Thin sheet metal behind the gasket, or will that just force the exhaust to eat way at the rest of the gasket..

[Chryco Psycho]

I use a piece of the old intake gasket cut to size , silicone it into the opening

[GoodysGotaCuda]

The Felpro I used last time blocked it, it's a composite gasket. The exhaust burns right through it..

[Bullitt-]

I've read someone suggested flat stainless steel... I have some if you need.

[femtnmax]

I used 0.018 thick stainless steel sheet from hardware store, cut at least 1/8 inch larger on each side than the opening in the head.  Then placed intake gasket to head.  Relied on 'crush' of intake gasket to allow intake manifold to lay flat.  Worked perfect, and never leaked, never burned thru.  I glued the Ssteel to head so it would not move around when intake manifold was attached.  Used 3M weatherstrip and let it set up some before installing the intake manifold.

[Aussie Challenger]

A piece of stainless shim on both sides I also have made a piece of metal that fitted into the head and silconed it in. Do you have the original exhaust manifolds and the exhaust cross over valve, if it is still there make sure that the valve is jammed open. With headers there shouldn't be much pressure so the exhaust should flow out the pipes.